1914 organising the troops in Ireland. He was a very reluctant supporter of John Redmond's takeover of the Volunteers and was ultimately the leader of the National Volunteers after the Volunteer split. Moore finally broke with Redmond in 1916 after the Easter Rising. In that year he collected a petition with Agnes O'Farrelly asking for a reprieve of the death sentence against Roger Casement. From 1917 on, he was a member of Sinn Féin, which led to his Dublin home being raided a number of times by the authorities during the Irish War of Independence. In 1920 he was appointed as Irish envoy to the Union of South Africa. His most important role as a diplomat was to persuade the South African Prime Minister General Smuts to support Irish independence, but he also understood that Smuts did not have the power to recognise the Irish Republic. As a result, when Smuts was in London for the 1921 Imperial Conference, he detoured to Dublin, met Éamon de Valera, and assisted both sides in brokering the Truce of July 1921 that ended the Irish War of Independence. Political career In 1922 he was made a member of the Irish Free State Seanad by W. T. Cosgrave. As a result of the Irish Civil War members of the Anti-Treaty IRA were attacking property belonging to senators. On 1 February 1923 Moore Hall, his ancestral home, and the property of his brother George, was totally destroyed. Moore and Jennie Wyse Power were the only two senators to oppose the election of Lord Glenavy as Cathaoirleach as he had been a former prominent Unionist. He and Wyse Power would both become increasingly vocal in opposition to Cumann na nGaedheal governmental policies. He was a vocal critic of the Boundary Agreement which was made between Ireland and the United Kingdom in 1925 and this persuaded him to join Clann Éireann which had been founded by Professor William Magennis. When the Ultimate Financial Settlement was signed he proposed a motion that it was prejudicial in the interests in the country. He famously said: "We have been burgled and we have bribed the burglar." In 1928 six Fianna Fáil candidates were elected to the Seanad under the leadership of Joseph Connolly and Moore immediately joined the party (Clann Éireann had already folded and encouraged its members to join Fianna Fáil). He was nominated as a candidate for Leas-Chathaoirleach